Insulating a metal shop?

Anything would be better than nothing, though those metal studs will still conduct some heat to the interior. For an example, I insulated a metal garage door that sees direct sunlight to help keep my garage cooler in the summer. I used foam boards similar to the ones posted in post #1. It helped a lot with heat transferring from the door panels themselves, but the door frame members still get warm to the touch when the sun is beating down on the outside of the door.

Does the shop receive direct sunlight? If so, each on of those metal studs will be a longer heater on sunny days if they're in contact with the outside panel unless you somehow insulate those as well.